The invention relates to a snow blower attachment for attachment to a conventional rotary lawnmower, particularly for removal of snow and other lightweight particulate materials such as leaves etc.
Snow blower attachments for rotary lawnmowers have been proposed for many years, and can provide an economical snow blower to reduce the work of clearing paths and driveways after a snowfall. Because the lawnmower is not usable during the winter seasons for cutting grass, connecting a snow blower attachment to the lawnmower extends the use of the lawnmower through a period when it would normally be unusable.
Some of the prior art snow blower attachments are designed to be attached to the existing standard cutter blade of the lawnmower, and thus require attachments of relatively small accessories, usually to tips of the blade which can be time consuming as sometimes several nuts and bolts and required for each attachment. Furthermore, if the nuts and bolts are not properly secured, or if there is "lost motion" between the blade and accessories, the accessories can become loosened due to the vibration, and can be thrown from the blade, thus exposing the operator or other persons nearby to risk. Other prior art attachments provide a complete blade or arm which is substituted for the standard cutter blade, and thus eliminates the problem of accidental loss of attachments mounted on the standard blade. Some of these devices are relatively complex and costly to manufacture, and might be prone to damage if they accidentally contact a hard object during use.
Also, some prior art devices require intake or exhaust duct accessories to be fitted to the existing stationary housing surrounding the blade and this requires more work to convert the lawnmower to a snow blower and vice versa. Other devices discharge the snow through an existing grass cuttings discharge opening in the housing which is a more common arrangement. Some prior art blades provide a vertical plate-like pushing device which is designed to push against the snow prior to spinning the snow within the housing of the lawnmower, which spinning eventually forces the snow through the discharge opening. Such devices might operate reasonably well in relatively light snow, but encounter difficulty when the snow has become frozen or partially packed, because a normal lawnmower has insufficient power to break up a large volume of snow. Other types of blades tend to lift or scoop the snow upwardly from its surface, but do not seem to provide a sufficient force to eject the snow through the discharge opening, and thus tend to require a great deal of power for operation. Typical prior art attachments are shown in U.S. Pat. No. 2,984,919 issued to Stoddard; U.S. Pat. No. 2,991,567 issued to Erickson; U.S. Pat. No. 3,043,036 issued to Trojanek and U.S. Pat. No. 3,373,514 issued to Forren.
There appears to be no snow blower attachments for attachment to a rotary lawnmower which are specifically designed to cut harder or packed snow into small portions initially, and then to exert a positive driving force tending to force the small portions of snow outwardly through the discharge opening, thus providing more clearance for recently cut snow to be subsequently ejected through the discharge opening.